The present invention relates to a cassette changer capable of housing a plurality of tape cassettes for a VCR or the like and sequentially operating these cassettes.
Various auto cassette changers have been proposed and well known; these cassette changers are principally used for business or broadcasting. Further, various cassette changers have been proposed which comprise a mechanism for chucking a groove formed in a cassette to install or withdraw the cassette, the mechanism being provided in a cassette transporting section for transporting the cassette between a recording and reproducing unit such as a VCR and a cassette storage section. A representative well-known example of such a cassette changer is described in JP-A-9-180329.
The cassette changer described in JP-A-9-180329 has a VCR, a rack acting as a cassette storage section, and a robot hand acting as the cassette transporting section. The robot hand has hooks provided at its right and left positions. Each of the hooks can be freely opened and closed and is urged in a closing direction by means of a first spring. When the hooks are closed, their tip portions engage with the groove of the cassette to enable the cassette to be held. Each hook is provided with a sublever. Each sublever can be freely opened and closed and is urged in a closing direction by means of a second spring.
The VCR has first eject guides each provided at a position corresponding to the hook and having a tapered surface. In addition, the rack has second eject guides each provided on a corresponding side surface thereof at a position corresponding to the sublever.
If a cassette held by the hooks of the robot hand is inserted into the VCR, the insertion causes the first eject guides to open the hooks, thereby disengaging the hooks from the cassette. Then, a pressure section of the robot hand presses the cassette into the VCR.
If the cassette is inserted into the rack, the sublevers abut on the second eject guides to release the hooks from the groove. Then, the cassette is housed in the rack at a predetermined position. In addition, if the cassette is removed from the rack, sublevers are prevented from abutting on the second eject guides, so that the hooks engage with the groove of the cassette instead of being released. Thus, the cassette can be withdrawn.
However, the above well-known cassette changers have the following problems:
A first problem is that the VCR cannot be directly operated without provision of the first eject guides therefor and that in some cases VCR must be substantially changed so as to include the first eject guides.
A second problem is that the rack also requires as many second eject guides as housed cassettes and must thus have a complicated structure.
A third problem is that the cassette changer requires a complicated structure because it cannot operate only with the hooks but requires the sublevers, the first and second springs, and the pressure section or the like.
A fourth problem is that if the robot hand executes movements required to house a cassette in the rack and take out another cassette, then after the housing of the cassette in the rack has been completed, the sublevers must be separated from the second eject guides and then moved to the cassette to be removed next, thereby requiring a large amount of time for cassette change.
It is a first object of the present invention to provide a cassette changer that can reliably change cassettes without the need to modify a VCR.
It is a second object of the present invention to provide a cassette changer having such a simple configuration as to eliminate the needs for sublevers, first and second springs, a pressure section, and second eject guides provided for each corresponding rack.
It is a third object of the present invention to provide a cassette changer that can be moved, immediately after a cassette has been housed in a rack, to another cassette to be removed next, thereby reducing the time required to change the cassettes.
To attain these objects, a cassette changer according to the present invention which comprises a recording and reproducing unit having an insert and withdrawal port and from which a groove-carrying cassette can be inserted and withdrawn, and a storage unit adapted to store a plurality of cassettes therein, and which is used to transfer the cassette between the recording and reproducing unit and storage unit, further comprises:
a first transfer unit for transferring the cassette between a first position from which the cassette can be transferred to the insert and withdrawal port of the recording and reproducing unit and a second position from which the cassette can be transferred to the storage unit;
a second transfer unit mounted on the first transfer unit for transferring the cassette between a movable position that does not hinder movement of the first transfer device and a storage position at which the cassette is housed in the storage unit or an insert and withdrawal position at which the cassette is inserted into or withdrawn from the insert and withdrawal port formed in the recording and reproducing unit;
a chuck mounted on the second transfer unit and which is capable of assuming a locking position in which it engages with the groove of the cassette to hold the cassette and a release position in which it leaves the groove of the cassette and does not hinder the first transfer means from moving; and
a chuck releasing member provided on the first transfer unit and allowing the second transfer unit to transfer the cassette to the storage or insert and withdrawal position and further move to abut on the chuck member to move it from the locking position to the release position.
Thus, the present invention has the following effects:
First, since operations can be completed only by the cassette transfer section, no changes need be made to the recording and reproducing unit, thereby enabling an totally inexpensive cassette changer to be realized.
Second, the first transfer unit has the chuck release member and the transfer operation performed by the second transfer unit enables cassette transfer and chuck releasing to be carried out, so that the first transfer unit can transfer the cassette immediately after the cassette has been housed in the storage unit, thereby reducing the time required to change cassettes.
According to a preferred embodiment of the present invention, the chuck comprises a groove engaging section that can engage with the groove of the cassette and an abutting section that can abut on one side surface of the cassette, and can assume, in addition to the locking and release positions, a push-in position in which the abutting section can abut on the one side surface of the cassette to push it into the storage unit or the insert and withdrawal port of the recording and reproducing unit. In addition, the chuck release member moves the chuck from the release position to the push-in position when the second transfer unit moves after the second transfer unit moves the chuck from the locking position to the release position.
With this embodiment, the transfer operation performed by the second transfer unit enables the performance of the cassette transfer operation, the chuck releasing operation, and the push-in operation. Accordingly, the chuck and the storage unit can be implemented using very simple configurations, thereby realizing an inexpensive cassette changer.
According to another preferred embodiment, the groove engaging section and the abutting section of the chuck are formed of an identical part. With such a configuration, the cassette can be inserted into the cassette storage unit or the recording and reproducing unit using a more simple arrangement.